Outlook certificate mismatch errors (On premises Exchange / SBS)

If you are using – usually with SBS installations – the self signed certificate with your on-premises Exchange server, you may find that you get ‘Certificate Mismatch’ warning dialogues when using Outlook.

There are a myriad of reasons why this may occur, but you can try and suppress them, or troubleshoot if you believe it to be a DNS problem (e.g. catch all DNS entry interfering with the autodiscover process).